Degradation and cytotoxicity of lotus-type porous pure magnesium as potential tissue engineering scaffold material

The lotus-type porous pure magnesium was prepared using a metal/gas eutectic unidirectional solidification method (GASAR process). The corrosion behavior, decay of mechanical property and the cytocompatibility were evaluated with the compact pure Mg as control. The porous pure Mg indicates better corrosion resistance than that of compact pure Mg in SBF at 37 °C. The compressive yield strength of compact and porous pure Mg is (110.3 ± 8.5) MPa and (23.9 ± 4.9) MPa before immersion test, and porous pure Mg exhibits slower decay in compressive yield strength with the extension of immersion period than that of compact pure Mg. With larger exposed surface area, porous pure Mg shows higher Mg concentration in the extract than that of compact pure Mg, which leads to a higher osmotic pressure to cells and might affect its indirect cytotoxicity assay result, but is still within the Grade I RGR value (no toxicity), implying the feasibility as potential tissue engineering scaffold.